* closeout.c (close_stdout): Don't assume 'bool' converts nonzero

[gnulib.git] / lib / closeout.c

diff --git a/lib/closeout.c b/lib/closeout.c
index bdda59f..2137fd4 100644 (file)
--- a/lib/closeout.c
+++ b/lib/closeout.c
@@ -1,5 +1,7 @@
 /* closeout.c - close standard output
-   Copyright (C) 1998, 1999, 2000 Free Software Foundation, Inc.
+
+   Copyright (C) 1998, 1999, 2000, 2001, 2002, 2004, 2006 Free
+   Software Foundation, Inc.
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -13,60 +15,42 @@
 
    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software Foundation,
-   Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
 
-#if HAVE_CONFIG_H
+#ifdef HAVE_CONFIG_H
 # include <config.h>
 #endif
 
-#if ENABLE_NLS
-# include <libintl.h>
-# define _(Text) gettext (Text)
-#else
-# define _(Text) Text
-#endif
-
-#if HAVE_STDLIB_H
-# include <stdlib.h>
-#endif
-#ifndef EXIT_FAILURE
-# define EXIT_FAILURE 1
-#endif
+#include "closeout.h"
 
 #include <stdio.h>
-
+#include <stdbool.h>
 #include <errno.h>
-#ifndef errno
-extern int errno;
-#endif
 
-#include "closeout.h"
+#include "gettext.h"
+#define _(msgid) gettext (msgid)
+
 #include "error.h"
+#include "exitfail.h"
 #include "quotearg.h"
 #include "__fpending.h"
 
-static int default_exit_status = EXIT_FAILURE;
-static const char *file_name;
+#if USE_UNLOCKED_IO
+# include "unlocked-io.h"
+#endif
 
-/* Set the value to be used for the exit status when close_stdout is called.
-   This is useful when it is not convenient to call close_stdout_status,
-   e.g., when close_stdout is called via atexit.  */
-void
-close_stdout_set_status (int status)
-{
-  default_exit_status = status;
-}
+static const char *file_name;
 
 /* Set the file name to be reported in the event an error is detected
-   by close_stdout_status.  */
+   by close_stdout.  */
 void
 close_stdout_set_file_name (const char *file)
 {
   file_name = file;
 }
 
-/* Close standard output, exiting with status STATUS on failure.
-   If a program writes *anything* to stdout, that program should `fflush'
+/* Close standard output, exiting with status 'exit_failure' on failure.
+   If a program writes *anything* to stdout, that program should close
    stdout and make sure that it succeeds before exiting.  Otherwise,
    suppose that you go to the extreme of checking the return status
    of every function that does an explicit write to stdout.  The last
@@ -74,11 +58,9 @@ close_stdout_set_file_name (const char *file)
    the fclose(stdout) could still fail (due e.g., to a disk full error)
    when it tries to write out that buffered data.  Thus, you would be
    left with an incomplete output file and the offending program would
-   exit successfully.
-
-   FIXME: note the fflush suggested above is implicit in the fclose
-   we actually do below.  Consider doing only the fflush and/or using
-   setvbuf to inhibit buffering.
+   exit successfully.  Even calling fflush is not always sufficient,
+   since some file systems (NFS and CODA) buffer written/flushed data
+   until an actual close call.
 
    Besides, it's wasteful to check the return value from every call
    that writes to stdout -- just let the internal stream state record
@@ -89,29 +71,31 @@ close_stdout_set_file_name (const char *file)
    on being able to detect failure in other tools via their exit status.  */
 
 void
-close_stdout_status (int status)
+close_stdout (void)
 {
-  int e = ferror (stdout) ? 0 : -1;
-
-  if (__fpending (stdout) == 0)
-    return;
+  bool none_pending = (__fpending (stdout) == 0);
+  bool prev_fail = (ferror (stdout) != 0);
+  bool fclose_fail = (fclose (stdout) != 0);
 
-  if (fclose (stdout) != 0)
-    e = errno;
-
-  if (0 <= e)
+  if (prev_fail || fclose_fail)
     {
-      char const *write_error = _("write error");
+      int e = fclose_fail ? errno : 0;
+      char const *write_error;
+
+      /* If ferror returned zero, no data remains to be flushed, and we'd
+        otherwise fail with EBADF due to a failed fclose, then assume that
+        it's ok to ignore the fclose failure.  That can happen when a
+        program like cp is invoked like this `cp a b >&-' (i.e., with
+        stdout closed) and doesn't generate any output (hence no previous
+        error and nothing to be flushed).  */
+      if (e == EBADF && !prev_fail && none_pending)
+       return;
+
+      write_error = _("write error");
       if (file_name)
-       error (status, e, "%s: %s", quotearg_colon (file_name), write_error);
+       error (exit_failure, e, "%s: %s", quotearg_colon (file_name),
+              write_error);
       else
-       error (status, e, "%s", write_error);
+       error (exit_failure, e, "%s", write_error);
     }
 }
-
-/* Close standard output, exiting with status EXIT_FAILURE on failure.  */
-void
-close_stdout (void)
-{
-  close_stdout_status (default_exit_status);
-}